<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS选择器</title><style>
    #id1{color: cyan;}
    /*所有的元素是**/
    *{}
    .id1{background-color: red}
    h1,h3{color: green}
    /*ul li{color: aqua}*/
    /*div>ul>li{color: blue}*/
    /*div>ul>li:first-child{color: red}*/
    /*div>ul>li:last-child{color: red}*/
    div>ul>li:nth-child(4){color: red}
</style>
</head>
<body>
<h1 id="id1" style="color: white;">test asdf   test</h1>
<p class="id1">this is a p</p>
<h3>test h3</h3>

<div>
    <ul>
        <span>test first-child</span>
        <li>li1</li>
        <li>li2</li>
        <li>li3</li>
        <ul>
            <li>li-ul-li1</li>
            <li>li-ul-li2</li>
        </ul>
    </ul>
</div>

</body>
</html>